Thermowells are commonly used in industry to protect sensitive temperature measurement instruments such as thermocouples, RTDs (Resistance Temperature Detectors), or thermometers from conditions of process fluids that may cause the bare instrument to suffer damage. The claimed invention relates to a new configuration for the construction of such thermowells for use in unusually difficult industrial applications such as pharmaceutical and chemical process plants, semiconductor manufacturing facilities and other similar facilities with process environments that may include some or all of:                Highly corrosive fluids        Difficult mechanical conditions such as rapid or turbulent fluid flows        Reasonably high process temperatures and/or pressures.        
In such industrial applications, maintaining tight control over process temperatures via quick detection and feedback of temperature changes is highly desirable to maintain the most efficient and effective processes. This problem is usually taken care of by employing carbon steel, stainless steel or other common metal thermowells. For highly corrosive environments where common metals do not stand up, the wells may be coated with corrosions resistant materials such as PTFE or made from solid PTFE or similar material.
In certain cases where unusually aggressive instances of the situations described above are encountered, PTFE jackets much thicker than coatings are employed, often with corrosion resistant tantalum cups to improve the sensitivity may be employed.
However all the above solutions have limitations that prevent their use in the most aggressive environments while achieving sensitivities that foster efficient processes. They may:                Have length limitations        Not be strong enough to handle fast moving or agitated fluids or        If fabricated to overcome such limitations, lose sensitivity slowing reaction times to process temperature changes.        
These situations provide an opportunity to overcome such limitations by using a combination of some previously employed design elements plus new design elements in a unique combination that allows much improved fluid temperature measurement and control in aggressive fluid environments.